Bis-meta-phenylene ureas and their utility as herbicides

ABSTRACT

BIS-META-PHENYLENE UREAS HAVING THE FORMULA:   1-(R1-N(-R2)-C(=X)-NH-),3-(R3-N(-R4)-CO-NH-),Z-BENZENE   IN WHICH X REPRESENTS OXYGEN OR SULFUR, R1 REPRESENTS LOWER ALKYL OR LOWER ALKENYL, R2 IS HYDROGEN, R3 REPRESENTS ALKYL, ALKENYL, CHLOROACETYL, PHENYL AND CHLORO SUBSTITUTED PHENYL, R4 REPRESENTS HYDROGEN, LOWER ALKYL AND FURFURYL, AND Z REPRESENTS HYDROGEN OR LOWER ALKYL. THE COMPOUNDS OF THIS INVENTION ARE USEFUL AS HERBICIDES.

United States Patent US. Cl. 260-552 R 2 Claims ABSTRACT OF THEDISCLOSURE Bis-meta-phenylene ureas having the formula:

X R1 Hit-4H.

in which X represents oxygen or sulfur, R represents lower alkyl orlower alkenyl, R is hydrogen, R represents alkyl, alkenyl, chloroacetyl,phenyl and chloro substituted phenyl, R represents hydrogen, lower alkyland furfuryl, and Z represents hydrogen or lower alkyl. The compounds ofthis invention are useful as herbicides.

' This is a division of application Serial No. 80,120, filed October 12,1970, now US. Patent No. 3,707,556.

This invention relates to certain novel substituted bismeta-phenyleneureas which are useful as herbicides. The compounds of the presentinvention are new compositions of matter and corresponding to thegeneral formula:

in which X represents oxygen or sulfur, R represents lower alkyl orlower alkenyl, R is hydrogen, R represents alkyl, alkenyl, chloroacetyl,phenyl and chloro substituted phenyl, R represents hydrogen, lower alkyland furfuryl, and Z represents hydrogen or lower alkyl.

In the above description, the following preferred embodiments areintended for the various substituent groups: lower alkyl preferablyincludes, unless otherwise provided for, those members which containfrom 1 to 6 carbon atoms, inclusive, in both straight chain and branchchain configurations, for example methyl, ethyl n-propyl, isopropyl,n-butyl, sec.-butyl, amyl, isoamyl, n-hexyl, isohexyl, and the like; theterm lower alkenyl preferably includes those members of the groupcontaining at least one olefinic bond and containing from 3 to 6 carbonatoms,

inclusive. X is defined as oxygen or sulfur, preferably oxygen 9 Thecompounds of this invention have been found to be active herbicides of ageneral type. That is, certain members of the class have been found tobe herbicidally effective against a wide range of plant species. Amethod of controlling undesirable vegetation of the present inyentioncomprises applying an herbicidally effective amount oftheabove-described compounds to the area or plant locus where control isdesired.

An herbicide is used herein to mean a compound which controls ormodifies the growth of plants. By a growth Patented June 11, 1974controlling amount" is meant an amount of compound which causes amodifying eflFect upon the growth of plants. Such modifying effectsinclude all deviations from natural development, for example, killing,retardation, defoliation, desiccation, regulation, stunting, tillering,stimulation, dwarfing and the like. By plants it is meant germinantseeds, emerging seedlings, and established vegetation including theroots and above-ground portions.

The compounds of the present invention are prepared by several differentmethods, depending upon the nature of the starting materials and theproducts desired. For example, the bis-meta-phenylene ureas are preparedby reacting a suitable aminophenyl urea with a suitable isocyanate orcarbamyl chloride. The symmetrical ureas are obtained by employing thesame reagents with meta-phenylene diamine. The reactions proceed readilyin the liquid phase. The employment of a solvent is also useful,facilitating processing, as well as agitation of the reactants. Solventssuch as acetone are conveniently employed. The reactions are carried outat temperatures that permit operation int he liquid phase. Thesetemperatures are between about room temperature and reflux temperatureof the solvent, if a solvent is employed. Generally, the reactionmixture is refluxed at an elevated temperature for several hours. Whenusing a carbamyl chloride as one of the reagents, it is preferably toemploy an acid acceptor such as potassium carbonate to facilitate thereaction. After the reaction is completed, the recovery of the crudeproduct is carried out by normal work-up procedures such ascrystallization, sublimation or distillation.

The compounds of the present invention and their preparation are moreparticularly illustrated by the following examples. Following theexamples is a table of compounds which are prepared according to theprocedures described "ice herein.

EXAMPLE I Preparation of Bis-1,1'-meta-phenylene-3,3-dimethyl-3'- methylurea l-Meta-amino phenyl 3,3-dimethyl urea, 12.5 g., is dissolved in ml.of acetone and 4.4 g. of methyl isocyanate added. The mixture is heatedat reflux for 2 hours, cooled and the product crystallizes fromsolution. Trituration with hot isopropyl alcohol gives 3 g. of product,M.P. 335337 C.

EXAMPLE 11 Preparation of Bis-1,l'-m-phenylene-3-methyl-3'- isopropylurea l-Meta-amino phenyl-3-methyl urea, 11.3 g., is dissolved in 100 ml.of acetone and 6 g. of isopropyl isocyanate. The mixture is heated toreflux for 2 hours, cooled and the product crystallizes from solution.Trituration of the solid product gave 8.7 g., M.P. 300 C.

EXAMPLE III Preparation of bis-1,1'-m-phenylene-3,3-diethyl- 3'-methylurea l-meta-amino phenyl-3-methyl urea, 9.9 g., is dissolved EXAMPLE IVPreparation of bis-1,1'-m-phenylene-3,3'-t-butyl urea Meta-phenylenediamine, 7.6 g. is dissolved in 100 ml. of acetone and 15.4 g. oft-butyl isocyanate added. The

and the crystalline product filtered off, washed with petroleum etherand dried. Yield is 4 g., of the title compound, M.P. 230-233 C. withsublimation.

The following is a table of the compounds which are is as follows:

weeds in several untreated control flats. The rating system -=nosignificant injury (approximately -10 percent control) =slight injury(approximately -40 percent control) prepared according to theaforementioned procedures. ++=mo"derate injury (approximately -70percentcon- Compound numbers have been assigned to them and are n 1) Iused for identification throughout the balance of the e i j or d h(approximately-70400 specification. percent control) 1 I TABLEI X /B1HlTTiL N O R; z g N --N\ H R;

M.P.( 0.), Compound No. R1 R1 R1 R4 X Z an H CH: CH: 8 H 123-126 H CH:CH; 0 H 335-337 H 02H; H o H 210-213 H l-CsHr H O H 300 H t-CtHn H O H202-204 H n-C4Hp H o H 250 H n-C4H0 H 0 H 190-195 H CQHE H o H 300 Hm-olctHr- H o H 300 H t-CtHo H O H 340-344 H CHr=CH-CH H O H 323.324 Hi-CaH1 H O H 343347 H t-C4Ho H 0 H 230-233 H 1-C:H1 H O H 331-335 Hn-CaH1 H O H 350 H CHz=CH-CHr H O 11 314.3 9 H 02H; H 0 H 326-328 H CH1H 0 2-011. 352-355 H 0H=0100 H o H 195 H 01H; 01 0 H 70-73, g

H CH| 0 H fln =L5720 CH l u 22 I-C=H1 H CH1 0 H 221-223 23 t-CJI. H CH:CH, 0 H nD= =L570o Decomposed.

HER'BICIDAL SCREENING TESTS An activity index is used to represent thetotal activity As previously mentioned, the herein described compoundsproduced in the above-described manner are phytotoxic compounds whichare useful and valuable in controlling various plant species. Compoundsof this invention are tested as herbicides in the following manner.

Pre-em'ergence herbicide test On the day preceding treatment, seeds ofseven different weed species are planted in individual rows using onespecies per row across the width of the fiat. The seeds used are hairycrabgrass (Digitaris sanguinalis (L.) Sc0p.), yellow foxtail (Setarzaglauca (L) Beauv.), watergrass (Echinochloa crusgalli (L.) Beauv.),California red oat (Avena sativa (L.)), redroot pigweed (Amaranthusretoflexus (L.)), Indian mustard (Brassica juncea (L.) Coss.) and curlydock (Rumex cripus (L.)). Ample seeds are planted to give about 20 toseedlings per row, after emergence, depending on the size of the plants.The flats are watered after planting. The spraying solution is preparedby dissolving 50 mg. of the test compound in 3 ml. of a solvent, such asacetone, containing 1% Tween 20 '(polyoxyethylene sorbitan monolaurate).The following day each flat is' sprayed at the rate of 20 pounds of thecandidate compound per 80 gallons of solution per acre. An atomizer isused to spray the solution onto the soil surface. The flats are placedin a greenhouse at 80 F. and watered regularly. Two Weeks later thedegree of weed control is determined by comparing the amount ofgermination and growth of each weed in the treated flats withPost-emergence herbicide test 1 Seeds of five weed species, includinghairy crabgrass, watergrass, California red oats, Indianmustard, andcurly dock and one crop, pinto beans (Phaseolus vulgaris), are plantedin flats as described above for pre-emergence screening. The flats areplaced in the greenhouse at 72- -F. and watered daily with a sprinkler.About 10 to 14 days after planting, when the primary leaves of the beanplant are almost fully expanded and the first trifoliate leaves are juststarting to form, the plants are sprayed. The spray is prepared byweighing out 50 mg. of the test compound, dissolving it in 5 ml. ofacetone containing 1% Tween 20 '(polyoxyethylene sorbitan monolau'rate)and then adding 5 ml. of water. The solution is sprayed on the foliageusingan atomizer. The spray concentration is 0.5% and the ratewould beapproximately 20 lbJacr'e if all of the spray were retained on the plantand the soil, but some spray is lost so it is estimated that theapplication rate is approximately 12.5 lb.'/a'cre.

' Beans" are used to detect defoliants and plant growth regulators. Thebeans are trimmed to two or three plants per flat by cutting off theexcess weaker plants several days before treatment. The treated plantsare placedback in the greenhouse and care is taken to avoid'sprinkling-the treated foliage with water for three days aftertreatment. Water is applied to the soil by means of a slow stream from awatering hose taking care not to wet the foliage.

Injury rates are recorded 14 days after treatment. The rating system isthe same as described above for the preemergence test where and are usedfor the different rates of injury and control. The injury symptoms arealso recorded. The maximum activity index for complete control of allthe species in the postemergence screening test is 18 which representsthe sum of the plus marks obtained with the six plant species used inthe test. The herbicide activity index is shown in Table 11.

TABLE II.HERBICIDAL ACTIVITY SCREENING RESULTS Herblcidal activity indexPre-emer- Post-emergenes (20 lb./a.)

2l=70-100% control of all seven plant species tested preemergence.18=70-l00% control of all six plant species tested post-emergence.

The compounds of the present invention are used as pre-emergence orpost-emergence herbicides and are applied in a variety of ways atvarious concentrations. In practice, the compounds are formulated withan inert carrier, utilizing methods well-known to those skilled in theart, thereby making them suitable for application as dusts, sprays, ordrenches and the like, in the form and manner required. The mixtures canbe dispersed in water with the aid of a wetting agent or they can beemployed in organic liquid compositions, oil and water, water in oilemulsions, with or without the addition of wetting, dispersing oremulsifying agents. An herbicidally effective amount depends upon thenature of the seeds or plants to be controlled and the rate ofapplication varies from 1 to approximately 50 pounds per acre.

The phytotoxic compositions of this invention employing an herbicidallyeiiective amount of the compound described herein are applied to theplants in the conventional manner. Thus, the dust and liquidcompositions can be applied to the plant by the use of power-dusters,boom and hand sprayers and spray-dusters. The compositions can also beapplied from airplanes as a dust or a spray because they are efiectivein very low dosages. In order to modify or control growth of germinatingseeds or emerging seedlings, as a typical example, the dust and liquidcompositions are applied to the soil according to conventional methodsand are distributed in the soil to a depth of at least inch below thesoil surface. It is not necessary that the phytotoxic compositions beadmixed with the soil particles and these compositions can be appliedmerely by spraying or sprinkling the surface of the soil. The phytotoxiccompositions of this invention can also be applied by addition toirrigation water supplied to the field to be treated. This method ofapplication permits the penetration of the compositions into the soil asthe water is absorbed therein. Dust compositions, granular compositionsor liquid formulations applied to the surface of the soil can bedistributed below the surface of the soil by conventional means such asdissing, dragging or mixing operations.

The phytotoxic compositions of this invention can also contain otheradditaments, for example, fertilizers, pesti cides and the like, used asadjuvant or in combination with any of the above-described adjuvants.Other phytotoxic compounds useful in combination with the abovedescribedcompounds include, for example, 2,4-dichlorophenoxyacetic acids,2,4,S-trichlorophenoxyacetic acid, 2-methyl-4-chlorophenoxyacetic acidand the salts, esters and amides thereof; triazine derivatives, such as2,4-bis (3 methoxypropylamino)-6-methyl thio S triazine; 2-

chloro-4-ethylamino-fi-isopropylamino S triazine, and 2-ethylamino-4-isopropylamino-6-methylmercapto S triazine, ureaderivatives, such as 3-(3,4-dichlorophenyl)-1, l-dimethyl urea and3-(p-chlorophenyl)-l,1-dimethyl urea and acetamides such asN,N-diallyla-chloroacetamide, N-(a-chloroacetyl)hexamethylene imine, andN,N-diethyla-bromacetamide, and the like; benzoic acids such as3-amino-2,5-dichlorobenzoic; and thiocarbamates, such as S-propyldipropylthiocarbamate; S-ethyl-dipropylthiocarbamate,S-ethyl-cyclohexyl-ethyl-thiocarbamate, S-ethylhexahydro-lg-azepine-l-carbothioate and the like. Fertilizers useful incombination with the active ingredients include, for example, ammoniumnitrate, urea and superphosphate. Other useful additaments includematerials in which plant organisms take root and grow, such as compost,manure, humus, sand and the like.

The concentration of a compound of the present invention, constitutingan eifective amount in the best mode of administration in the utilitydisclosed, is readily determinable by those skilled in the art.

Various changes and modifications are possible with out departing fromthe spirit and scope of the invention described herein and will beapparent to those skilled in the art to which it pertains. It isaccordingly intended that the present invention shall only be limited bythe scope of the claims.

What is claimed is:

1. A compound having the formula in which R represents lower alkyl, Rrepresents lower alkyl and R represents lower alkyl.

2. A compound according to claim 1 in which R is methyl, R is methyl andR is methyl.

References Cited UNITED STATES PATENTS 3,386,955 6/1968 Nawakowski eta1. 260-553 A 3,184,301 5/1965 Martin et a1. 260553 A 3,119,865 1/1964Weakley et a]. 260553 A LEON ZITVER, Primar Examiner M. W. GLYNN,Assistant Examiner

